<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
</head>
<style>
    /* 关于overflow:hidden的作用（溢出隐藏、清除浮动、解决外边距塌陷等等） */
    
    .box {
        background: skyblue;
        overflow: hidden;
        /*清除浮动*/
        zoom: 1;
    }
    
    .kid {
        width: 100px;
        height: 100px;
        float: left;
    }
    
    .kid1 {
        background: yellow;
    }
    
    .kid2 {
        background: orange;
    }
    
    .wrap {
        width: 300px;
        height: 150px;
        background: blue;
        color: white;
    }
</style>

<body>
    <div class="box">
        <div class="kid kid1">子元素1</div>
        <div class="kid kid2">子元素2</div>
    </div>
    <div class="wrap">其他部分</div>
</body>

</html>